1. Field of the Invention
The present invention relates to liquid crystal displays (LCDs) and, more particularly, to an LCD panel and a method of improved patterning of indium-tin oxide (ITO) for precision-cutting and aligning of the LCD panel.
2. Description of Related Art
A liquid crystal display (LCD) is a thin, lightweight display device that has no moving parts. It consists of an electrically-controlled, light-polarising liquid that is trapped in cells between two transparent polarising sheets. The polarising axes of the two sheets are aligned perpendicular to each other. Each cell is supplied with electrical contacts that allow an electric field to be applied to the liquid inside.
LCDs that have a small number of segments, such as those used in digital watches and pocket calculators, are supplied with one electrical contact for each segment. The electrical signal used to drive each segment is supplied from an external circuit. Small and medium-sized displays have a passive matrix structure, which has one set of contacts for each row and column of the display, rather than one for each pixel.
A conventional LCD consists of an upper glass substrate and a lower glass substrate positioned in spaced parallel relation. One or more transparent electrodes are formed on the upper surface of the lower glass substrate. One or more transparent electrodes are also formed on the lower surface of the upper glass substrate. The liquid crystal material is sandwiched between the two glass substrates and a polarizing film is added to the outer side of each substrate. Because an LCD requires backlighting in order to provide the light source for each pixel, the glass substrate is formed of a transparent material, such as glass and the electrodes are also formed of a transparent, electrically conductive material, such as ITO.
Because each panel of an LCD is formed of a transparent substrate that has transparent electrodes, there are no visible features that are useful in performing a precision cutting operation in the manufacture thereof and, thus, the accuracy to which an LCD panel may be sized is limited. Furthermore, the lack of visible features is prohibitive for aligning one LCD panel to another.
Therefore, what is needed, and not disclosed in the art, is a method of providing visible features for accurately cutting and grinding a transparent substrate that has transparent ITO lines formed thereon to a desired precise dimension and visible features for use in aligning one LCD panel to another.